CVE-2021-36766

Public Exploit

Description

Concrete5 through 8.5.5 deserializes Untrusted Data. The vulnerable code is located within the controllers/single_page/dashboard/system/environment/logging.php Logging::update_logging() method. User input passed through the logFile request parameter is not properly sanitized before being used in a call to the file_exists() PHP function. This can be exploited by malicious users to inject arbitrary PHP objects into the application scope (PHP Object Injection via phar:// stream wrapper), allowing them to carry out a variety of attacks, such as executing arbitrary PHP code.

Category

7.2
CVSS
Severity: High
CVSS 3.1 •
CVSS 2.0 •
EPSS 1.54% Top 20%
Third-Party Advisory packetstormsecurity.com Third-Party Advisory seclists.org Third-Party Advisory hackerone.com
Affected: n/a n/a
Published at:
Updated at:

References

Link Tags
https://hackerone.com/reports/1063039 third party advisory permissions required
http://seclists.org/fulldisclosure/2021/Jul/36 mailing list exploit third party advisory
http://packetstormsecurity.com/files/163564/Concrete5-8.5.5-Phar-Deserialization.html exploit vdb entry third party advisory

Frequently Asked Questions

What is the severity of CVE-2021-36766?
CVE-2021-36766 has been scored as a high severity vulnerability.
How to fix CVE-2021-36766?
To fix CVE-2021-36766, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-36766 being actively exploited in the wild?
It is possible that CVE-2021-36766 is being exploited or will be exploited in a near future based on public information. According to its EPSS score, there is a ~2% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
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